1. Field of the Invention
The present invention relates to a pressed workpiece inspection apparatus that is provided in a press line particularly one including a destack feeder section, a press-molding section, and a palletizer section, and is configured to inspect whether or not a pressed workpiece is non-defective.
2. Description of the Related Art
Conventionally, the body of a vehicle or the like is formed by press-molding (plastic-molding) a plate material (work) such as steel or aluminum into the shape of a curved surface with intricate patterns of bulges and recesses by using a transfer press-molding machine, a tandem press-molding machine, or the like. Such a workpiece undergoes press-molding plural times by plural dies so as to be gradually formed into a final shape. Consequently, compared with the case where the final shape is formed by press-molding a single time, the molding process can be divided into sub-processes and thus a molding time can be reduced, thereby improving the overall production efficiency.
In the case where press-molding is performed plural times in this manner, press-molding is successively shifted (in approximately 3 seconds) from a current press-molding step to a subsequent press-molding step. Accordingly, it is difficult to arrange the timing of and a period of time for inspection of whether or not the pressed workpiece has a crack or the like. Thus, there has been a need to devise an inspection method and/or an inspection timing that can reduce the time taken to inspect whether or not the pressed workpiece is non-defective.
As an inspection apparatus that inspects whether or not the pressed workpiece is non-defective (or defective), for example, there is known a technology described in Japanese Unexamined Patent Application Publication (JP-A) No. 2006-170684 (FIGS. 1 and 2). The technology described in JP-A No. 2006-170684 (FIGS. 1 and 2) provides a mechanism including a transmission probe configured to generate ultrasonic waves, and a reception probe configured to receive the ultrasonic waves, these probes being moved over an object to be inspected (target pressed workpiece to be inspected). Each probe is moved back and forth over the object to be inspected at a predetermined scanning pitch, and subsequently, an image of the shape, size, or the like of a crack is captured using an infrared camera or a flash device, and then it is determined whether or not the object is non-defective, based on the captured data.
However, in the inspection apparatus described in the JP-A No. 2006-170684 (FIGS. 1 and 2) mentioned above, the inspection is performed using ultrasonic waves while each probe is moved back and forth over the object to be inspected at a predetermined scanning pitch, and subsequently, it is determined whether or not the object is non-defective, based on the resultant image captured by the infrared camera. Consequently, it takes a longer time for the determination, and furthermore, the inspection requires various pieces of equipment (each probe, a drive mechanism to move each probe, an infrared camera, a flash device, and the like). Thus, it is difficult to apply the inspection apparatus to a transfer press-molding machine or the like, and also the inspection apparatus tends to increase in size.